Cambridge 16 | Test 4 | Passage 1

Roman tunnels

The Persians, who lived in present-day Iran, were one of the first civilizations to build tunnels that provided a reliable supply of water to human settlements in dry areas. In the early first millennium BCE, they introduced the qanat method of tunnel construction, which consisted of placing posts over a hill in a straight line, to ensure the tunnel kept to its route, and then digging vertical shafts down into the ground at regular intervals. Underground, workers removed the earth from between the ends of the shafts, creating a tunnel. The excavated soil was taken up to the surface using the shafts, which also provided ventilation during the work. Once the tunnel was completed, it allowed the water to flow from the top of a hillside down towards a canal, which supplied water for human use. Remarkably, some qanats built by Persians 2,700 years ago are still in use today.

millennium (noun) [countable]

/mɪˈlen.i.əm/

a period of 1,000 years, or the time when a period of 1,000 years ends

Imagine what the world will be like at the end of the next millennium.

post (noun) [countable]

a vertical stick or pole stuck into the ground, usually to support something or show a position

She tied the dog to a post.

shaft (noun) [countable]

a long, either vertical or sloping, passage through a building or through the ground

a lift/elevator shaft